Um, I thought when the camera was set to focus-release, it will fire regarldess of whether focus was achieved?

Yes and no. There is a subtle distinction in how this works that seems to elude some on DPR. When set to Focus release the camera MUST have at least obtained a focus one time. When in AF-C mode the camera will continue to fine tune focus as long as you keep the AF-ON button pressed. If you move the AF spot over a different target while holding down the AF-ON buttion the focus will change. But when you press the shutter button the camera will take the picture. Regardless of whether the area under the current AF point is in focus or not.

If the camera has NEVER achieved a single focus lock while in Focus release mode it will NOT allow you to trip the shutter. This is subtle but it is an important difference.

If you are in AF-C single point mode with Focus priority set... if you aim the camera at a blank featureless wall the camera will NOT allow you to trip the shutter. If you get close to a picture frame but do NOT let the AF point drift over the frame you still will not be able to take a picture. But let the AF point drift over the picture frame for even an instant and the camera will lock focus. You can now take a photo no matter where you point.

You guys are confusing me. What the heck is "Focus release"? Are you talking about Focus priority, Release priority, or Release+Focus priority?